Piston



. "March 2o, 1945. 2,372,050

J. BARRAJA-FRAUENFELDER ET AL ATT NEY Patented Mar. 20, 1945 UNITE D STATES PTE OFF! C E aa'zaos f Y i PISTON J osephf Barraia'Fxvauenfclder..1UpperV Montclair, :v and Oscar G.. Schrom, Montclair, N. J., assign orsv to. Americane Locomotive` Company. New York, NL Y... a corporationof ew. York ApplcatonlAuguSt 6, 1943,- Serla-l- No.497 ,660l f i L7 claims..y (creta- 19).

This invention relatesl toI pistons; and'moreparticularly to an internal combustion engine` piston having arotative body.

object of "the present invention is to provide an improved pistn having a rotative body-r' f:

A further object is. to provide' a piston'-'a.s

aforesaid, having a rotative body'- anda`= sena` rate non-rotative Wrist pin carrier. and means connecting the body and carrier adaptedlto withstand the forces-towhich thel pistonis'sub-'f jeoted.

A vfurther object is to provide apistonas'Y aforesaid provided with improved cooling andlubricating. means.

Other. and further objects-of this# invention' e will appearfrom the followingv description;` theaccomp'anying drawings and 1 the: appended claims... y

Referring to the drawings-forming'a-partof this:` application, Figure 1` i'sacentral' vertical section taken on the line. I-IV of'Eig. 2, shovvel ingl the piston. of. the present inventionanelfal portionof the cylinder and connecting radins-*- sociated therewith, parts.- being shownT full; Fig. 2 is a sectionaon the line-II-IIlof Figglf; Fig. Sis, at the right',A a. section on the`lineIII-'III of. Fig. 1, and at .the left, aninvertedplan, othei piston; Fig. 4^is aplan vieWfof'thevvristpinicaar'- rier; Fig. 5 is a section on they line2V-'-V.oiFi`g`-il 4; Fig. 6- is a View similar to Fig.;4 1',..ta-lrenlA omtlie i line. VI-VI of Fig. 7, of a modicationlof the'A present invention; Fig. 7. is az section;,ontherllne VII-VII of Fig. 6; Fig.. 8 is a section on the-line VIII- VIII of Fig... 7;. Fig., elevation of;`

thev Wrist pin carrier ci Fig. 6; Fig.: mais, at vthe`l` right, a. plan oi Fig. 9,.and,.v at .theleft, .a section. on the line X-X of Eig; 9f; Fig. lLiszan inverted:l plan` of the piston of Fig- 6;, partly: broken away;

Fig. 12. is an inverted. plan of the retaineriof Fig.. 1. with certain of the associatedjpartsshowir; dot. and. dash, lines; andllig...1-3fiszarrenlarged. fragmentary section of` the bottom; portion not" theskirt similar' to.` that. showneiatf-the right'lini.

Fig.. 1, j Referring; morel particularlyftn Figs;` 1`5 off-thc;

drawings; only a. portion of the..v cylinder.1 Il of@V the internal' combustion. engine is-Ishowm the cylinder-is.'disposed'acompositepistori 2 mnirite'elll on a. connectingl rod` 3;

The piston 2 hasiarotative 4piston body lli-iiiKnr cluding a thin-walled headV Slandl a thin-walled skirt 6:.-- Piston rings-'Pare disposedlinlpisten v off the inner face of the cylinder' aredispcsecffm laterabtongues 21"' fitting; in grooves f I8.

ments.A 261i are. secured in place bytapbolts 301 grooves- 9" the grooves`v being best shown in the enlargedView,` Figav 13) intthcv bottom portion of the skirt,-groovesill draining'V back tothe engi-ne cran-le case (not shown) bymean'soffbores- It;

1 An annular transverse vvalli-orflangey I I extends radially# inwardly' from the'inner lfacel of the skirt 6 and is reinforced byA WebsH I2* formed integral- W-ith' therlange Kandiwith"the inner face offthefskirtabove the` ange. Immediately beneaththe flangel'lywhicli'haea nat transwerseL bottom face f3; the skirtfisthick, providing a rim l# having an inner' cylindrical lface I i'concentric' witlr-the-pistonbody i; The-bottom portionofv they skirt is also thick, providing` a rim AIfi'lraving -an inner cylindrical `face-Il-ilrlinewithl face l5. Immediately belowthe'fa'ce' Ill?, four cylindrical.

tracks; or grooves ff areI formedin .the 'inner' side portion. 25' in engagement with? face. Il. Car-r rier-L2 I: isf secured in this position Aby a retainer formedof :two segmentsf 26; each` of whichl has Segextendingthrougn oriices 3| inthe-A segments. and beingscrewed into threadedl .oriiicesl 32 in carrier All lof theV engagements` between the carrieriand piston body'v have sulcientfreedom. toi. permit slidingA rotative: movement therebetween. v

Th'ecarrer rurtherfhas alignedwristpin bearings13-3' providedi withlbushings/ 3d, andi, at vright angles. thereto, alignedffWeight-reducing openings 35. Lubricating grooves lfareA formedI in theiinner facelofthef-bushing.- A lubricating and cooling oil receiver 3l is formed"integral with 'tha-face 221 off. the: carrier.- The receiver hasfa central passage 138flfunne1v-shape'df transversely ofij tl'ie wrist.. pin' bearingi The receiver, at they opposite inclined ends thereoi, has but a single wa11.-3'9(Fi'g. 2), but,- at' right" angles-thereto it' has; atleachside; anfinner wal-l `4`0 andan outer spaced'iwall CIII'IGIigQ-lllf Anforiilcel wie formed in each of the outer walls 4I. The walls 39 and 4I are contiguous with the face 22. The connecting rod 3 is provided with a boss 43, having a top face 44 curved concentrically with the axis of the wrist pin bearings 33, and the receiver 31 at its bottom, formed by the bottom faces 45 and 43 of walls 39 and 40, respectively, is curved similarly to the curvature of face 44 and slightly spaced therefrom.

The connecting rod 3 is conventional in structure and is therefore only shown fragmentally.

flange II. This oil is splashed generously over the adjacent surfaces of the piston head, skirt and carrier, cooling them. Passage 38 forms the inlet of the cooling chamber 51 and the outlet is formed by the orifices 42 in the outer walls 4I of the receiver 31. The oil enters the space between the walls 40 and 4I by means of the orifices 42 and ows downward over the surfaces of the wrist pin and connecting rod and into the grooves 36 of bushings 34, lubricating same.

Some oil in the cooling chamber 51 also leaks It has a wrist pin bearing 41 in its upper end, provided with a bushing 48 secured therein against rotation by a lock screw 49., It further has a central longitudinal bore 5B adapted to be connected at the bottom of the connecting rod with a source of lubricating oil under pressure (not shown)l and opening at` its top into the funnel-shaped passage 38. Bore 5B has a portion below the Wrist pin bearing 41 and a portion above the Ywrist pin bearing, the latter passing through boss 43, bore 5D thereby being intersected by the bearing 41. The two portions of bore 50 are connected around the bushing 48 by a groove 5I which is connected, 'by bores 52, with lubricating grooves 5 3 formed in the inner face of bushing 48. f

A hollow wrist pin 54, disposed for free rotation in bushings 34and 48, nsecures the connecting rod to the carrier. The wrist pin ends 55 arecurved spherically concentric to the inner face of the rim I9 which the'ends are adapted to engage to prevent lateral displacement movement of the wrist pin.

Before assembling the 'parts of the piston together, the connecting rodisinserted into the hollow interior of the carrier, and the wrist pin is slid into the bushings 34L and 48 through a side of the carrier. Then the carrier, withthe connecting rod securedvthereto, is moved into the piston body until the face 22 engages the face I3 by means of the shim 23. The segments 26 are then inserted in the body 4 beneath the carrier 2I so that the tongues 21 are in their respective grooves I8, and the orifices 3| and 32 of the segmentsrand carrier respectively are in alignment. The tapbolts 35 are thenscrewed into place,securing the parts of the piston together.

Piston 2 is especially adapted for employment in a four-cycle engine wherein the suction stroke imposes a force on the means connecting the wrist pin carrier to the piston body, in the present instance on the tongues 21 of the segments and on the portion of the body 4 containing the grooves It. On the power stroke, the force is taken by the flange II. The flange II, the body adjacent ,the grooves I8, andthe segments are made sufficiently strong to withstand the forces to which they are subjected. Webs 56 formed integrally with the top andside walls of the carrier strengthen it around the receiver 31. It will be obvious that piston 2 will workas well in other cycle engines, for instancein a two-cycle engine wherein theoretically all the forces will be taken by the flange II.

The lubricating and cooling` cycle of the piston is as follows:

Oil under pressure ispumped upwardly through the bore Eiland into groove 5I. Some of the oil lubricates bushing 48 through the bores 52 and grooves 53. Theremainderof the oil passes into the funnel-shaped passage 38, from which it overflows into a chamber 51 formed by the hollow interior of vthe pistonl body above the through the sliding fit between the flange I I and the face 22 and between the portion 24 and face I5, and the oil draining from the portion 24 and from the bushings 34 lubricates the portion 25,l face I1, the tongues 21 and the grooves I8. Thus all 'engaging faces between the piston body and carrier are well lubricated and cooled, assisting in oating the piston body on the carrier for rotative movement. Openings 35 prevent accumulation of Voil between the carrier and piston body.

The piston body is of relatively thin construction, as the thick wrist pin bosses are part of the carrier, and therefore expansion and contraction in the piston body is more uniform than in conventional one-piece pistons. Also, due to the ability of the piston body to rotate, more even transmission of heat from the piston head 5 to the cooling fluid is eected. Similarly, the carrier with its wrist pin bosses, being separated from the ,piston body, is not subjected to severe heat transfer therefrom and heat stresses in the carrier are also avoided. Uneven expansion and contraction of the carrier, if it occurs, due to heavy metal concentration, does not aifect the piston body, due to the freedom between these members. Thus the necessary clearance between the cylinder and the body is small.

A modification of the present invention is shown in Figs. 6-11. In this embodiment parts corresponding to similar parts in the embodiment of Figs. l5 will be designated by the same reference numeral with an accent added, and only a brief description thereof will be given.

The piston 2' has .a thinner head 5 than the piston 2 and therefore it is desirable to support the piston head 2 on the wrist pin carrier 2I Thediierences in structure between the two embodiments shown in the drawings are caused by this difference in the thickness of the piston heads. In general piston 2 is like piston 2, but insteadof the flange II, it has an annular wall or flange Il' formed by the bottom of a hollow boss 5B which depends from the head 5. The bossv 58 has an orice 59 in its bottom and four orifices 60 in its side walls.

The carrier 2l is secured in the piston 2 similarly to the manner in. which the carrier 2I is secured in the piston 2, the carrier 2i having an upper face 22' engaging, by means of a shi-n1 23', the bottom flat face I3 of iiange Il'. The carrier 2|' has a receiver 31 provided with a central passage 38' which opens through the orifice 59 for iiow of cooling and lubricating oil into the interior of the boss 58, and therefrom through the orifices 60 into the chamber 51' between the carrier 2l and the adjacent walls of the piston.

The oil leaves the chamber 51through orifices While there have been hereinbefore described approved embodiments of this invention, it ywill be understood that many and various changes and modications in form, arrangement of parts and details of construction thereof may be made l without departing from the spirit of the invention, and that all such changes and modications as fall within the scope of the appended claims are contemplated as a part of this invention.

The invention claimed and desired to be secured by Letters Patent is:

1. A piston comprising a body having a hollow cylindrical interior housing portion and an internal transverse wall at the inner end of said housing portion; a hollow cylindrical wrist pin carrier disposed in said housing portion, having a face at its inner end slidably engaging the outer face of said wall; and a segmental retainer bolted to said carrier at the outer end thereof, saidkretainer and body having a slidable tongue-and,- groove-like connection whereby said bodyis rotatably mounted on said carrier.

2. A piston comprising a body member having a hollow cylindrical interior housing portion and an internal transverse annular flange at the inner end of said housing portion; a hollow cylindrical wrist pin carrier member disposed in said housing portion, having a transverse face at its inner end slidably engaging the outer face of said ilange and a receiver providing a` passage for -a cooling and lubricating medium extending inwardly from said transverse face through the center of said annular ange; and a retainer adjacent the outer end of said carrier member secured to one of said members and slidably engaging the other of said t members whereby said body member is rotatably mounted on said carrier member.

3. A piston comprising' a hollow body member having a head, a skirt and an internal transverse annular flange extending radially inwardly from the inner face of'said skirt at a portion thereof spaced outwardly from said head; a hollow cylindrical carrier member disposed in said'body member having a bore for a wrist pin, a transverse face at its inner end slidably engaging the outer face of said iiange' and a receiver providing a passage for a cooling and lubricating medium extending inwardly from said transverse face through the center of said annular flange, said carrier member and flange cooperating to provide in said hollow interior of said body memy and having opposed sets of double spaced walls,

f ing into said chamber, forming outlets for said chamber, the space between said walls of each at both ends forming an inlet for said chamber,

the outer wall oi each set being oriiiced and openset communicating with said bore; and a retainer adjacent the outer end of said carrier member, secured to one of said members and slidably engaging the other of said members whereby said` body member is rotatably mounted on said carrier member.

5. A piston comprising a hollow body member having a head and a skirt; a rhollow cylindrical carrier member disposed in said body member, having a bore for a Wrist pin, a transverse inner wall and va receiver providing a passage for a cooling and lubricating medium open at its outer end to said bore and open at its inner end through said wall, said body member further having a hollow boss exten-ding from said head'toward, and having an outer transverse face slidably engaging said carrier member inner wall, and open interiorly to said passage open outer end, said carrier inner wall having an opening affording communication between the interior thereof and the interior of said piston at its `inner end portion, and said hollow boss having an opening in a side wall thereof affording communication between the interior thereof and said piston in terior at its said inner 'end portion; and a retainer adjacent the outer end of said carrier member, secured to one. of said members and slidably engaging the other of said members whereby said bodymember is rotatably mounted on said carrier member.

6. In combination with a wrist pin and a connecting rod mounted thereon having alongitudinal bore for the passage therethrough of a cool` ing and lubricating medium, a piston comprising a hollow body member having an internal transverse wall; a hollow cylindrical carrier member mounted on said wrist pin, having a wall with a face slidably engaging the outer face of said transverse wall; a receiver extending from said ber inwardly of said flange, a chamber for said 4. A piston comprising'a hollow body member having a head, a skirt and an internal transverse annular flange extending radially inwardly from the inner face of said skirt at a portion thereof spaced outwardly from said head; a hollow cylindrical carrier member disposed in said body member having a bore for a wrist pin, a transverse face at'its inner end slidably engaging the outer face of said flange and a receiver providing a passage for a cooling and lubricating medium extending inwardly from said transverse face through the center of said annular flange, said carrier member and flange cooperating to provide in said hollow interior of said body member inwardly of said ilange, a chamber for said cooling and lubricating medium, said passage being open u carrier member wall, open at its inner and outer ends providing a passage forl said medium, said passage being at its outer end slightly spaced from said connecting rod and having itsouter end opening in communication with said bore;

and a rretainer adjacent the outer end of said f carrier member, secured to one of said members and slidably engaging the other of said members whereby said body member is rotatably lmounted on said carrier member.

7. A piston comprising a hollow body member having4 a head and a skirt, said skirt having a housing portion provided with a cylindrical wall and said head having an integral boss extending to said housing portion provided with a transverse face at its outer end; a hollow carrier member disposed in said housing portion provided with a bore for a wrist pin and a cylindrical wall slidably engaging said housing portion cylindrical wall for free rotative relative movement therebetween and further having at its inner end a transverse wall slidably engaging said boss transverse face for permitting said rotative relative movement and for supporting said head;` and a retainer adjacent the outer end of said carrier member, secured to one of said members and slidably engaging the other of said members, permitting said rotative relative movement.

JOSEPH BARaAJA-FRAUENFELDER. oscAR G. scHRoM. f 

